title: Effects of dilution rate and water reuse on biomass and lipid production of Scenedesmus obliquus in a two-stage novel photobioreactor.
abstract: Continuous culture of fresh water microalgae Scenedesmus obliquus was developed in a two-stage photobioreactor, avoiding the intermediate harvesting step to achieve a half-way point between the progressive and the sudden N-starvation strategies, guaranteeing light limited conditions in the first stage and N-stress conditions in the second stage. This methodology resulted in biomass productivity values at the best dilution rate (0.118 days(-1)) of 15.25±1.06 g m(-2) d(-1), slightly higher than that expected according to batch experiment (12.90±0.75 g m(-2) d(-1)). The dilution rate that maximized the lipid content was coincident with that for the maximum biomass productivity, resulting in a intensification of the lipid productivity. Microalgae can be successfully cultured in reused medium clarified by high pH flocculation-sedimentation and neutralized by bubbling the photobioreactors outlet CO2 current through it. Microalgae flocculation with NaOH does not result in a variation of the obtained lipid profile.
authors.affiliation: BIOBAS, Research and Development Department, 1 Rualasal St., 39001 Santander, Cantabria, Spain. lucasml@biobas.es
authors.forename: L M
authors.initials: LM
authors.lastname: Lucas-Salas
authors.forename: M
authors.initials: M
authors.lastname: Castrillo
authors.forename: D
authors.initials: D
authors.lastname: Martínez
mesh_terms: D018533:Biomass; D019149:Bioreactors; D050356:Lipid Metabolism; D008055:Lipids / Q000096:biosynthesis*; D055668:Photochemical Processes; D044444:Scenedesmus / Q000378:metabolism*
chemical_list: D008055:Lipids
keywords: Continuous culture; Microalgae; N-starvation; Photobioreactor; Two-stage processing